In digital broadcasting, a TV signal is compressed to a digital signal carrying at least an audio-visual (AV) data for broadcasting. Typically upon reception, a digital TV renders or displays the AV data carried in the digitalized TV signal. The success of the digital TV mainly results from development and implementation of Motion Picture Experts Group 2 (MPEG-2) and MPEG-4 video compression technologies.
For example, a digital broadcasting system is a US Advanced Television Systems Committee (ATSC) system or a European Digital Video Broadcasting-Terrestrial (DVB-T) system. Examples of the middle ware technology of the digital broadcasting include a DVB multimedia home platform (DVB-MHP), an OpenCable application platform (OCAP), and an advanced common application platform (ACAP). DVB-MHP is a middle ware system applied to the European digital TV designed in the DVB project. OCAP is a middle ware system applied to the US Cable Corporation. ACAP is comparable to the OCAP applied to cable broadcasting and a digital TV application software environment (DASE) applied to ground-ware broadcasting.
In addition to AV data transmission, the digital broadcasting system is able to broadcast content file data such as a webpage file, text file, or audio file. A digital storage media command and control (DSM-CC or DSM-CC) standard is a protocol for providing control functions and operations for managing transport streams, suitable for performing content file data broadcasting. DSMCC provides two methods for carrying data—data carousel and object carousel. The data carousel is applied to data transmission, and the object carousel is based on data carousels to provide files, indexes, and data streams to transmitted data. Elements of DSMCC carousels are contained in a DSMCC message. There are two types of DSMCC message: a DSMCC download data message and a DSMCC download control message. The DSMCC download data message comprises real data of a module, and the DSMCC download control message is used to inform a receiver how to form data into information of the module. For example, the DSMCC download data message is a download data block (DDB) message. The DSMCC download control message includes a download information indication (DII) message and/or a download server initiate (DSI) message.
According to the DSMCC data broadcasting standard, a module comprises a data object, such as a file. FIG. 1 shows a structure of the DVB data carousel. A module 12 comprises at least one block 11 transmitted as a DDB 111. The DDB 111 recording an MPEG data section is received by a DSMCC receiver in a received transport stream. In order to obtain an object from the broadcasting network, each module 12 containing the object is obtained. The transmission parameters of each module 12 such as a module version, a module size, a block size, timing, and a broadcasting channel, are recorded in a DII 131. In addition, in a complicated system, a plurality of groups 13 form a large group 14, and transmission parameters of the groups 13 are recorded in a DSI 141. Therefore, the DSMCC receiver of a digital TV combines the modules 12 to a group 13 after having received the DII 131, and combines the groups 13 to the large group 14 after having received the DSI 141, so that the digital TV is able to render and display the content file data in the transport stream.
The digital TV is provided with a firmware to associate with a processor for processing a received TV signal. When the video compression technology, the DSMCC standard, or an operating interface develops and changes, the firmware of the digital TV needs to be updated. In the prior art, the firmware is typically updated by connecting to a host computer via a connection interface. Alternatively, all firmware programs are compressed to a compressed file that is carried in a module 12 of a transport stream, and the digital TV in a night sleep state downloads the DDBs 111 of the module 12 to obtain the compressed file that is to be decompressed so as to update the firmware of the digital TV.